#include <stdio.h>
int main()
{
    char c;
    int letterChars = 0, digitalChars = 0, otherChars = 0;
    printf("please input data:\n");
    while ((c = getchar()) != '\n')
    {
        if (c >= 'a' && c <= 'z' || c >= 'A' && c <= 'Z')
            letterChars++;
        else if (c >= '0' && c <= '9')
            digitalChars++;
        else
            otherChars++;
    }
    printf("the letter numbers=%d\nthe digit numbers=%d\nthe other"
           " character number=%d\n",
           letterChars, digitalChars, otherChars);
}
